Optical bar code reading apparatus with signal processing circuit for eliminating regular reflection condition

ABSTRACT

An optical reading apparatus (bar code reader) including a plurality of light emitting elements, each light emitting element emitting light in different directions onto an information recording surface which has a linear recording (bar code pattern) printed thereon. A light receiving element receives reflected light from the information recording surface and generates a recording medium read signal for each light emitting element which is transmitted to a signal processing section. The signal processing section includes a plurality of conversion processing routes for converting the recording medium read signals from the plurality of light emitting elements into a plurality of display signals. Each of the display signals is then decoded separately. When a regular reflection condition occurs in a first display signal (that is, the first display signal does not produce a valid code), but does not occur in a second display signal (that is, the second display signal produces a valid code), then the signal processing circuit only outputs the accurately decoded display signal, thereby eliminating errors caused by the occurrence of the regular reflection condition.

This application is a division of application Ser. No. 08/512,052, filedAug. 7, 1995, now pending.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to an optical reading apparatus such as a barcode reader for reading a linear recording medium such as a bar code andconverting it into a display signal, and more particularly to an opticalreading apparatus such as a bar code reader which prevents reading of alinear recording medium from being disabled by a regular reflectioncondition which occurs upon reading of the linear recording medium,

2. Description of the Related Art

A bar code reader which reads a bar code performs conversion processingof the thus read bar code such as decoding and outputs a resulted signalas a required display signal conventionally includes a light emittingelement for emitting light to an information recording surface on whicha bar code is printed a light receiving element for receiving reflectedlight from the information recording surface and generating a bar coderead signal, a signal processing section for performing conversionprocessing of the bar code read signal such as amplification, binarydigitization, decoding and so forth and outputting a resulted signal asa required display signal, and a driving section for driving the lightemitting element.

FIG. 10 shows in block diagram an example of a construction of a knownbar code reader of the type described above. Meanwhile. FIGS. 11(a) and11(b) are signal waveform diagrams illustrating conditions of signals atseveral portions of the known bar code reader when a bar code is readand FIG. 12 is a schematic sectional view showing the known bar codereader during use.

As seen from FIGS. 10 and 12, a bar code 61 is printed on an informationrecording surface 61a. A light emitting element 62 formed from a lightemitting diode (LED) or a like element is located in the proximity of areading portion (end portion) of the bar code reader, and a lightreceiving element 63 formed from a photodiode array or a like device islocated a little rearwardly of the light emitting element 62 at thereading portion (end portion) of the bar code reader. Light emitted fromthe light emitting element 62 is reflected by the information recordingsurface 61a on which the bar code 61 is printed, and is then condensedby a lens 63a and introduced into the light receiving element 63 by wayof a pin hole plate 63b. The output of the light receiving element 63 isconnected to the input of an amplifier 64, and the output of theamplifier 64 is connected to the input of a binary digitizing circuit65. The output of the binary digitizing circuit 65 is connected to theinput of a decoding circuit 66, and the output of the decoding circuit66 makes the output of the bar code reader. In this instance, theamplifier 64, the binary digitizing circuit 65 and the decoding circuit66 constitute a signal processing section. A driving section 67 suppliesdriving power for driving the light emitting element 62.

Operation of the bar code reader having the construction described abovewill be described below with reference to FIGS. 11(a) and 11(b). Now, ifa user grasps the bar code reader in a hand so that the reading portion(end portion) of the bar code reader may be opposed to the informationrecording surface 61a on which the bar code 61 is printed, then lightemitted from the light emitting element 62 and irradiated upon theinformation recording surface 61a on which the bar code 61 is printed isreflected by the information recording surface 61a, and the reflectedlight is supplied to the light receiving element 63. Upon reception ofthe reflected light the light receiving element 63 generates a bar coderead signal and supplies the bar code read signal to the signalprocessing section constituted from the amplifier 64, the binarydigitizing circuit 65 and the decoding circuit 66. In the signalprocessing section, the bar code read signal is first amplified to apredetermined level by the amplifier 64 and then converted into a binarysignal by the binary digitizing circuit 65. Then the binary signal isdecoded by the decoding circuit 66, and the decoded signal from thedecoding circuit 66 is outputted as a display signal from the bar codereader. In this instance, when such a pattern of the bar code 61 as seenat the top stage in FIG. 11(a) is read, the amplified bar code readsignal waveform A appearing on the output side of the amplifier 64exhibits such a form of pulses corresponding to the bar code 61 as seenat the middle stage in FIG. 11(a) and the binary signal waveform Bappearing on the output side of the binary digitizing circuit 65exhibits such a binary signal corresponding to the bar code 61 as seenat the lower stage in FIG. 11(a).

It is to be noted that light to be irradiated from the bar code 61 uponthe information recording surface 61a on which the bar code 61 isprinted may be continuous light or intermittent light which has apredetermined timing pattern.

By the way, in the known bar code reader described above, in reading theinformation recording surface 61a on which the bar code 61 is printed,when the light irradiation angle at which light is irradiated from thelight emitting element 62 upon the information recording surface 61a onwhich the bar code 61 is printed and the light receiving angle at whichlight reflected from the information recording surface 61a on which thebar code 61 is printed is inputted to the light receiving element 63satisfy individual particular requirements, a condition wherein most oflight irradiated upon the information recording surface 61a on which thebar code 61 is printed is received as reflected light by the lightreceiving element 63, that is, a condition wherein the amount of lightreceived by the light receiving element 63 exhibits a sharp peakcondition occurs. This condition is normally called regular reflectioncondition. When such regular reflection condition is entered a largeamount of light is introduced into the light receiving element 63 at atime, and the bar code read signal extracted from the light receivingelement 63 exhibits a sudden variation to a very large amplitude. Thus,the amplifier 64 at the next stage is saturated by the bar code readsignal of the large amplitude thus inputted thereto, and consequently,at least part of bar code components of the bar code read signal is lostas seen from the signal waveform C of FIG. 11(b). If such bar code readsignal is inputted to the binary digitizing circuit 65, the binarydigitizing circuit 65 cannot extract the bar code components from withinthe bar code read signal due to the loss of at least part of the barcode components. Consequently, the binary digitizing circuit 65 cannotgenerate a binary signal corresponding to the bar code components asseen from the signal waveform D of FIG. 11(b) Further, since the binarysignal supplied from the binary digitizing circuit 65 to the decodingcircuit 68 does not include at least part of the binary signalcorresponding to the bar code components, the decoding circuit 66 cannotgenerate a decoded signal corresponding to the bar code components andaccordingly cannot output a required display signal from the bar codereader.

Consequently, with the known bar code reader described above, when sucha regular reflection condition as described above occurs, a readingoperation of the information recording surface 61a on which the bar code61 is printed is performed repetitively until bar code components areread, that is, until a required display signal is outputted from the barcode reader.

The known bar code reader described above, however, is disadvantageousin that, when a regular reflection condition occurs, much time isrequired for accurate reading of the bar code 81 because a readingoperation of the information recording surface 61a on which the bar code61 is printed must be performed repetitively until a required displaysignal is outputted from the bar code reader The known bar code readeris further disadvantageous in that, particularly where a user of the barcode reader is inclined to perform a reading operation of the bar code61 in a condition in which a regular reflection condition occurscomparatively likely, much more time is required to accurately read thebar code 61.

SUMMARY OF THE INVENTION

It is an object of the present Invention to provide an optical readingapparatus which can accurately read a linear recording mediumimmediately even if a regular reflection condition occurs

In order to attain the object described above according to an aspect ofthe present invention there is provided an optical reading apparatus,which comprises a plurality of light emitting elements for emittingintermittent or continuous light beams at a predetermined timing ortimings in different directions to an information recording sursurfaceon a linear recording medium thereon, a light receiving element forreceiving reflected light from the information recording surface andgenerating a recording medium read signal a signal processing sectionfor converting the recording medium read signal from the light receivingelements into a display signal, a controlling driving section fordriving the plurality of light emitting elements, and a regularreflection detection section for detecting occurrence of a regularreflection condition from the recording medium read signal from thelight receiving element and supplying a regular reflection detectionsignal obtained upon such detection to the driving controlling section,the driving controlling section controlling, when the regular reflectiondetection signal is supplied thereto from the regular reflectiondetection section, driving of the plurality of light emitting elementsin a different driving manner from that when the regular reflectiondetection signal is not supplied thereby to eliminate occurrence of theregular reflection condition.

In the optical reading apparatus, the regular reflection detectingsection detects occurrence of a regular reflection condition from therecording medium read signal from the light receiving element andsupplies a regular reflection detection signal, which is obtained whenoccurrence of a regular reflection condition is detected, to thecontrolling driving section. The driving controlling section controlswhen the regular reflection detection signal is supplied thereto,driving of the plurality of light emitting elements in the drivingmanner different from that when the regular reflection detection signalis not supplied thereto. More particularly, when the regular reflectiondetection signal is not supplied, the controlling driving section drivesonly one of the plurality of light emitting elements, but when theregular condition detection signal is supplied thereto, the controllingdriving section drives another one of the light irradiation sectionsdifferent from the one light irradiation section, to eliminate theoccurrence of the regular reflection condition, or when the regularreflection detection signal is not supplied thereto, the controllingdriving section drives all of the plurality of light emitting elements,but when the regular reflection detection signal is supplied thereto,the controlling driving section stops driving of the plurality of lightemitting elements one by one in order until occurrence of the regularreflection condition is detected no more, to eliminate the occurrence ofthe regular reflection condition, or else, when the regular reflectiondetection signal is not supplied thereto, the controlling drivingsection drives the plurality of light emitting elements intermittentlyat different timings from each other, but when the regular reflectiondetects an signal is supplied thereto, the controlling driving sectionimmediately stops driving of that one of the light emitting elementswith which the regular reflection condition occurs to eliminate theoccurrence of the regular reflection condition.

In this manner, with the optical reading apparatus, since thecontrolling driving section drives the plurality of light emittingelements suitably such that, when occurrence of a regular reflectioncondition is detected by the regular reflection detecting section, theoccurrence of the regular reflection condition may be eliminated, thereis an advantage in that reading of a linear recording medium to generatea display signal is not disabled at all irrespective of whether or not aregular reflection condition occurs and accurate reading of the linearrecording medium can be performed immediately.

According to another aspect of the present invention, there is providedan optical reading apparatus, which comprises a plurality of lightemitting elements for emitting intermittent light beams at apredetermined timing or timings in different directions to aninformation recording surface on a linear recording medium thereon, alight receiving element for receiving reflected light from theinformation recording surface and generating a recording medium readsignal, a signal processing section for converting the recording mediumread signal from the light receiving element into a display signal, anda controlling driving section for driving the plurality of lightemitting elements, the plurality of light emitting elements beingcontrolled to be driven by the controlling driving section so as to emitintermittent light beams at timings different from each other, thesignal processing section having a plurality of conversion processingroutes for individually performing conversion processing of a pluralityof recording medium read signals obtained individually from theplurality of light emitting elements, the signal processing sectionselectively extracting and outputting, as a display signal, that one ofthe recording medium read signals obtained by the conversion processingby the plurality of conversion processing routes which is in a goodcondition.

In the optical reading apparatus, driving of the plurality of lightemitting elements is controlled such that they irradiate intermittentbeams of light at different timings from each other, and the signalprocessing section has a plurality of conversion processing routes forindividually performing conversion processing of a plurality ofrecording medium read signals obtained individually for the plurality oflight emitting elements and selectively extracts and outputs, as adisplay signal, one of recording medium read signals obtained byconversion processing by the plurality of conversion processing routeswhich is in a good condition. More particularly when the plurality ofrecording medium read signals are decoded, one of the recording mediumread signals which has been decoded regularly is selectively extractedand outputted as a display signal, or occurrence of one of the pluralityof recording medium read signals with which a regular reflectioncondition occurs is detected, and another one of the plurality ofrecording medium read signals with which occurrence of a regularreflection condition is not detected is selectively extracted andoutputted as a display signal.

In this manner with the optical reading apparatus, there is an advantagein that, since that one of the plurality of recording medium readsignals which is in a good condition is selectively extracted andoutputted, reading of a linear recording medium to generate a displaysignal is not disabled at all irrespective of whether or not a regularreflection condition occurs and accurate reading of the linear recordingmedium can be performed immediately.

The above and other objects, features and advantages of the presentinvention will become apparent from the following description and Theappended claims, taken in conjunction with the accompanying drawings inwhich like parts or elements are denoted by like reference characters.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of an optical reading apparatus showing afirst preferred embodiment of the present invention;

FIG. 2 is a schematic sectional view showing the bar code reader of FIG.1 during use;

FIGS. 3(a) to 3(d) are signal waveform diagrams illustrating signals atseveral portions of the optical reading apparatus of FIG. 1 when a barcode is read;

FIG. 4 is a flow chart illustrating operations of detection ofoccurrence of a regular reflection condition and changing over betweenlight emitting elements in the optical reading apparatus of FIG. 1;

FIG. 5 is a block diagram of another optical reading apparatus showing asecond preferred embodiment of the present invention;

FIG. 6 is a block diagram of a further optical reading apparatus showinga third preferred embodiment of the present invention;

FIGS. 7(a) to 7(h)are signal waveform diagrams illustrating signalsseveral portion of the optical reading apparatus of FIG. 6 when a barcode is read;

FIG. 8 is a block diagram of a still further optical reading apparatusshowing a fourth preferred embodiment of the present invention;

FIG. 9 is a block diagram of a yet further optical reading apparatusshowing a fifth preferred embodiment of the present invention;

FIG. 10 is a block diagram showing an example of a construction of aknown bar code reader;

FIG. 11 is a schematic sectional view showing a known bar code readerduring use; and

FIGS. 12(a) and 12(b) are signal waveform diagrams illustrating signalsat several portions of the known optical reading apparatus of FIG. 11when a bar code is read.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the following, preferred embodiments of the present invention will bedescribed in detail with reference to the accompanying drawings.

FIG. 1 shows, in block diagram, an optical reading apparatus accordingto a first preferred embodiment of the present invention. The opticalreading apparatus shown is constructed as a bar code reader. Meanwhile,FIG. 2 shows, in schematic sectional view, the bar code reader duringuse.

Referring to FIGS. 1 and 2, a bar code 1 is printed, similarly to aknown bar code, on an information recording surface 1a. A pair of firstand second light emitting elements 2-1 and 2-2 each formed from a lightemitting diode (LED) or a like element are disposed at locationscomparatively in the proximity of a reading portion (end portion) of thebar code reader and a pair of optical transmission lines 3-1 and 3-2each formed from a glass fiber or a like element are interposed betweenthe first and second light emitting elements 2-1 and 2-2 and the readingportion (end portion). A light receiving element 4 formed from aphotodiode array or a like device is disposed in a juxtaposedrelationship to the first and second light emitting elements 2-1 and2-2. Light obtained from the first and second light emitting elements2-1 and 2-2 is projected outwardly by way of the optical transmissionlines 3-1 and 3-2 and is reflected by the information recording surface1a on which the bar code 1 is printed. The reflected light is firstcondensed by a lens 4a and then introduced into the light receivingelement 4 through a pin hole plate 4b. The output of the light receivingelement 4 is connected to the input of an amplifier 5, and the output ofthe amplifier 5 is connected to the input of a binary digitizing circuit6. The output of the binary digitizing circuit 6 is connected the inputof a decoding circuit 7, and the output of the decoding circuit 7 isconnected to the output of the bar code reader. Meanwhile, the output ofthe amplifier 5 is connected to the input of a regular reflectiondetecting circuit 8, and the output of the regular reflection detectingcircuit 8 is connected to the input of a controlling driving circuit 9.The output of the controlling driving circuit 9 is connected to thefirst and second light emitting elements 2-1 and 2-2 In this instance,the amplifier 5, the binary digitizing circuit 6 and the decodingcircuit 7 constitute a signal processing section.

FIGS. 3(a) to 3(d) illustrate, in signal waveform diagram, signals atseveral portions of the bar code reader of the first embodimentdescribed above when a bar code is read. In particular, FIG. 3(a),illustrates an example of a bar code pattern to be read; FIG. 3(b)illustrates a waveform of an amplified bar code read signal when noregular reflection condition occurs; FIG. 3(c) illustrates a waveform ofan amplified bar code read signal when a regular reflection conditionoccurs; and FIG. 3(d) illustrates a waveform of a binary signal.

Operation of the bar code reader of the first embodiment will bedescribed below with reference to FIGS. 3(a) to 3(d).

The first and second light emitting elements 2-1 and 2-2 are driven bythe controlling driving circuit 9 such that normally only one of them isin an operative condition. For example, when only the first lightemitting element 2-1 is in an operative condition, it generatesintermittent light or continuous light at a predetermined timing. Thelight generated from the first light emitting element 2-1 is introducedto the reading portion (end portion) of the bar code reader by way ofthe optical transmission line 3-1. In this instance, if a user graspsthe bar code reader in its hand and operates the bar code reader so thatthe reading portion (end portion) of the bar code reader is opposed tothe information recording surface 1a on which the bar code 1 (the barcode 1 has such a pattern as shown, for example, in FIG. 3(a)) isprinted, the light introduced from the first light emitting element 2-1to the reading portion (end portion) of the bar code reader isirradiated upon and reflected from the information recording surface 1aon which the bar code 1 is printed. The reflected light is condensed bythe lens 4a and supplied to the light receiving element 4 through a pinhole of the pin hole plate 4b. Upon such operation the pin hole plate 4bperforms scanning of the pin hole with respect to the light receivingelement 4. Consequently, reflected light equivalent to that obtainedwhen the information recording surface 1a on which the bar code 1 isprinted is scanned along the portion of the information recordingsurface 1a at which the bar code 1 is formed is received by the lightreceiving element 4. When the reflected light is received, the lightreceiving element 4 generates a bar code read signal having an amplitudecorresponding to the light amount of the reflected lights. The bar coderead signal is supplied to the signal processing section at thesucceeding stage which is constituted from the amplifier 5, the binarydigitizing circuit 6 and the decoding circuit 7. In the signalprocessing section, the bar code read signal is first amplified to spredetermined level by the amplifier 5 so that a bar code read signal ofsuch a waveform as seen in FIG. 3(b) is obtained from the amplifier 5.The bar code read signal is then binary digitized by the binarydigitizing circuit 6 so that a binary signal of such a waveform as seenin FIG. 3(d) is obtained from the binary digitizing circuit 6. Thebinary signal is decoded by the decoding circuit 7, and the thus decodedsignal is outputted as a display signal from the bar code reader.

The bar code read signal obtained at the output side of the amplifier 5is supplied also to the regular reflection detecting circuit 8, by whichit is detected whether or not the bar code read signal exhibitsoccurrence of a regular reflection condition. Then, if the regularreflection detecting circuit 8 detects that the bar code read signalinputted thereto exhibits no occurrence of a regular reflectioncondition, for example, as seen from FIG. 3(b), the regular reflectiondetecting circuit 8 continuously supplies a regular reflectionnon-detection signal to the controlling driving circuit 9 while suchdetection continues. When the regular reflection non-detection signal issupplied to the controlling driving circuit 9, the controlling drivingcircuit 9 continues driving of that one of the light emitting elementswhich has been driven by the controlling driving circuit 9 until thattime, here, driving of the first light emitting element 2-1 andconsequently, the first light emitting element 2-1 continues itsgeneration of intermittent light at the predetermined timing. On theother hand, if the regular reflection detecting circuit 8 detects fromthe bar code read signal inputted thereto that a reference level varies,at a first portion of the bar code read signal, by a Great amount in thenegative direction, for example, as seen in FIG. 3(c), that is, aregular reflection condition occurs, it immediately supplies a regularreflection detection signal to the controlling driving circuit 9. Uponreception of the regular reflection detection signal, the controllingdriving circuit 9 stops driving of that one of the light emittingelements which has been driven until that time, here driving of thefirst light emitting element 2-1 in order to eliminate the cause ofoccurrence of the regular reflection condition and simultaneously startsdriving of the second light emitting element 2-2 to thus performchanging over between the light emitting elements. As a result of thechanging over between the light emitting elements, generation ofintermittent light or continuous light from the first light emittingelement 2-1 is stopped while the second light emitting element 2-2begins to generate intermittent light or continuous light at thepredetermined timing. Consequently, the regular reflection conditionhaving occurred with the bar code read signal is eliminated immediatelyas seen from FIG. 3(c), and a bar code read signal whose reference leveldoes not exhibit a variation is obtained. Then, the bar code read signalthus obtained is binary digitized by the binary digitizing circuit 6 sothat such a binary signal as seen in FIG. 3(d) is obtained from thebinary digitizing circuit 6. The binary signal is decoded by thedecoding circuit 7 and outputted as a display signal from the bar codereader.

FIG. 4 illustrates in flow chart, the operations of detection ofoccurrence of a regular reflection condition and changing over betweenlight emitting elements in the bar code reader of the first embodimentdescribed above.

Principal operation of the bar code reader of the first embodiment willbe described again with reference to the flow chart of FIG. 4.

First at step S1 only one of the light emitting elements, for example,only the first light emitting element 2-1 is driven under the control ofthe controlling driving circuit 9, and intermittent light at apredetermined timing is generated from the first light emitting element2-1 The light is first reflected from the information recording surface1a on which the bar code 1 is printed, and then supplied to the lightreceiving element 4.

Then at step S2, scanning with respect to the light receiving element 4is started so that light obtained by scanning the information recordingsurface 1a on which the bar code 1 is printed is introduced into thelight receiving element 4. Consequently the light receiving element 4generates a bar code read signal having an amplitude corresponding tothe amount of light introduced into it. The bar code read signal issupplied to the signal processing section.

Then at step S3, the regular reflection detecting circuit 8discriminates whether or not the bar code read signal amplified by theamplifier 5 is higher than a regular reflection detection level. If theregular reflection detecting circuit 8 discriminates that the bar coderead signal is not higher than the regular reflection detection level(N), it outputs a regular reflection non-detection signal, whereafterthe control sequence advances to step S4. On the contrary, if theregular reflection detecting circuit 8 discriminates that the bar coderead signal is higher than the regular reflection detection level (Y),then it outputs a regular reflection detection signal, and the controlsequence advances to another step S5

At step S4, the controlling driving circuit 9 continues driving of thefirst light emitting element 2-1 in response to reception of the regularreflection non-detection signal.

On the other hand at step S5, in response to reception of the regularreflection detection signal, the controlling driving circuit 9 stopsdriving of the first light emitting element 2-1 and starts driving thesecond light emitting element 2-2 instead.

At step S6 subsequently to step S4 or S5, scanning with respect of thelight receiving element 4 is stopped.

Subsequently at step S7, the decoding circuit decodes the binary signalfrom the binary digitizing circuit 6 to generate a display signal.

In this manner with the bar code reader of the first embodiment of thepresent invention, when a regular reflection condition occurs with oneof the light emitting elements which is in use, for example, with thefirst light emitting element 2-1 the regular reflection detectingcircuit 8 detects the occurrence of the regular reflection condition andchanges over the light emitting element to be used to the other lightemitting element, for example to the second light emitting element 2-2.Consequently, the regular reflection condition is eliminatedimmediately. Accordingly, processing of a bar code read signal can beperformed normally in a regular condition free from occurrence of aregular reflection condition, and there is no necessity of repetitivelyperforming a reading operation of a bar code as a result of occurrenceof s regular reflection condition.

It is to be noted that while in the first embodiment described above thefirst and second light emitting elements 2-1 and 2-2 are employed as thelight emitting elements, the number of light emitting elements which canbe used in the present embodiment is not limited to two, and three ormore light emitting elements may otherwise be employed.

In this instance where three light emitting elements, for example, firstsecond and third light emitting elements, are employed, one of the threelight emitting elements, for example, the first light emitting element,is normally used and, if occurrence of a regular reflection condition isdetected during use of the first light emitting element, the lightemitting element to be used is changed over from the first lightemitting element to the second light emitting element or the third lightemitting element. This similarly applies to another other case whereinfour of more light emitting elements are employed.

FIG. 5 shows, in block diagram, an optical reading apparatus accordingto a second preferred embodiment of the present invention. Also in thisinstance, the optical reading apparatus is constructed as a bar codereader. In FIG. 5, like elements to those of FIG. 1 are denoted by likereference characters.

The bar code reader of the second embodiment is different inconstruction from the bar code reader of the first embodiment only inthat the light receiving element 4 does not output one bar code readsignal but outputs two bar code read signals corresponding to tworeflected light beams inputted thereto, that the light receiving element4 and the amplifier 5 are not coupled directly to each other, but anadding circuit 10 is connected between the light receiving element 4 andthe amplifier 5, and that the controlling driving circuit 9 does notdrive one of the light emitting elements, but normally drives the firstand second light emitting elements 2-1 and 2-2 simultaneously. Further,in the second embodiment, the amplifier 5, the binary digitizing circuit6, the decoding circuit 7 and the adding circuit 10 constitute a signalprocessing section.

The bar code reader of the second embodiment having the constructiondescribed above operates in the following manner.

First, the first and second light emitting elements 2-1 and 2-2 aredriven simultaneously under the control of the controlling drivingcircuit 9 so that intermittent light beams are generated simultaneouslyat a predetermined timing from the first to second light emittingelements 2-1 to 2-2. The two light beams are irradiated upon theinformation recording surface 1a printed on the bar code 1 and thenintroduced as two reflected light beams individually into the lightreceiving element 4. In this instance, the light receiving element 4generates two bar code read signals corresponding to the two reflectedlight beams inputted thereto, and supplies the two bar code read signalsto the two inputs of the adding circuit 10. The adding circuit 10 simplyadds the two bar code read signals to generate a single added bar coderead signal. The added bar code read signal is converted into a binarysignal by the binary digitizing circuit 6 and then decoded by thedecoding circuit 7 so that it is outputted as a display signal from thebar code reader. The added bar code read signal from the adding circuit10 is supplied also to the regular reflection detecting circuit 8, bywhich it is detected whether or not a regular reflection conditionoccurs with the added bar code read signal. If the regular reflectiondetecting circuit 8 detects that a regular reflection signal does notoccur with the added bar code read signal, then it supplies a regularreflection non-detection signal to the controlling driving circuit 9. Onthe contrary, if the regular reflection detecting circuit 8 detects thata regular reflection condition occurs with the added bar code readsignal, it supplies a regular reflection detection signal to thecontrolling driving circuit 9. If a regular reflection non-detectionsignal is supplied to the controlling driving circuit 9, then thecontrolling driving circuit 9 continues to drive the first and secondlight emitting elements 2-1 to 2-2 simultaneously on the contrary, if aregular reflection detection signal is supplied, then the controllingdriving circuit 9 stops driving of the first and second light emittingelements 2-1 to 2-2 one by one in order. In this instance, if theregular reflection condition of the added bar code read signal iseliminated when driving of the first light emitting element 2-1 isstopped, then the controlling driving circuit 9 stops driving of thefirst light emitting element 2-1 for a fixed period of time, forexample, for a time while reading of the bar code continues. On theother hand, if the regular reflection condition of the added bar coderead signal is not eliminated even if driving of the first lightemitting element 2-1 is stopped, driving the first light emittingelement 2-1 is resumed while driving of the second light emittingelement 2-2 is stopped instead. If the regular reflection condition ofthe added bar code read signal is eliminated as a result of the stoppingof driving of the second light emitting element 2-2, then driving of thesecond light emitting element 2-2 is stopped for the fixed period oftime, for example for a time while reading of the bar code continuessimilarly as above. Consequently, the regular reflection condition ofthe added bar code read signal is eliminated in a comparatively shorttime.

It is to be noted that, while, in the second embodiment described above,the first and second light emitting elements 2-1 to 2-2 are employed asthe light emitting elements the number of light emitting elements whichcan be employed in the present embodiment is not limited to two, andthree or more light emitting elements may otherwise be employed.

Further the bar code reader of the second embodiment may be modifiedsuch that, when driving of one of the plurality of light emittingelements is stopped, the driving voltage to the remaining light emittingelement or elements is raised a little so that the amplitude of theadded bar code read signal may be substantially fixed before and afterdriving of the one light emitting element is stopped.

In this manner with the bar code reader of the second embodiment, if aregular reflection condition occurs with one of the plurality of lightemitting elements 2-1 and 2-2 while all of the light emitting elementsare used, the regular reflection detecting circuit 8 detects theoccurrence of the regular reflection condition from the added bar coderead signal, and driving of the one light emitting element is stopped.In this manner since the plurality of light emitting elements 2-1 and2-2 are successively stopped from driving one by one in order until theregular reflection condition of the added bar code read signal iseliminated, the thus occurred regular reflection condition is eliminatedin a comparatively short time. Accordingly, processing of a bar coderead signal can be performed normally in a regular condition free fromoccurrence of a regular reflection condition, and there is no necessityof repetitively performing a reading operation of a bar code as s resultof occurrence of a regular reflection condition.

Further, with the bar code reader of the second embodiment, since thelight receiving element 4 generates a plurality of bar code read signalsin response to simultaneous irradiation of light beams from theplurality of light emitting elements 2-1 and 2-2 and signal processingsuch as generation of a binary signal, detection of a regular reflectioncondition and so forth is performed using an added bar code read signalobtained by addition of the bar code read signals generated from thelight receiving element 4, the signal processing can be performed with ahigh sensitivity.

FIG. 6 shows, in block diagram, an optical reading apparatus accordingto a third preferred embodiment of the present invention. Also theoptical reading apparatus of the present embodiment is constructed as abar code reader. Further, also in FIG. 6, like elements to those of FIG.1 are denoted by like reference characters.

The bar code reader of the third embodiment is different in constructionfrom the bar code reader of the first embodiment only in that first andsecond sample hold circuits 12 and 13 are newly connected to the outputside of the amplifier 5, that in place of the provision of the binarydigitizing circuit 6, first and second binary digitizing circuits 14 and15 are connected to the output sides of the first and second sample holdcircuits 12 and 13, respectively and besides a selecting circuit 16 forselecting a decoded signal is provided between the outputs of the firstand second binary digitizing circuits 14 and 15 and the decoding circuit7, that the input of the regular reflection detecting circuit 8 is notconnected to the output side of the amplifier 5 but two inputs of theregular reflection detecting circuit 8 are connected to the output sidesof the first sample hold circuit 12 and the second sample hold circuit13, and that the controlling driving circuit 9 does not drive one of thelight emitting elements but normally drives both of the first and secondlight emitting elements 2-1 and 2-2 so that the first and second lightemitting elements 2-1 and 2-2 may generate intermittent light beams atdifferent timings from each other. Here in the third embodiment, theamplifier 5, the decoding circuit 7, the first and second sample holdcircuits 12 and 13, the first and second binary digitizing circuits 14and 15 and the selecting circuit 16 constitute a signal processingsection.

FIGS. 7(a) to 7(h) are signal waveform diagrams illustrating signals atseveral portions of the bar code reader of the third embodiment when abar code is read. In particular, FIG. 7(a) shows an example of a barcode pattern to be read; FIG. 7(b) shows an output waveform ofintermittent light generated from the first light emitting element 2-1;FIG. 7(c) shows an output waveform of intermittent light generated fromthe second light emitting element 2-2; FIG. 7(d) shows an output signalwaveform of the amplifier 5, FIG. 7(e) shows an output waveform of thefirst sample hold circuit 12; FIG. 7(f) shows an output waveform of thesecond sample hold circuit 13; FIG. 7(g) shows a binary signal waveformof the first binary digitizing circuit 14; and FIG. 7(h) shows a binarysignal waveform of the second binary digitizing circuit 15. In thisinstance, FIGS. 7(a) to 7(h) illustrate a manner wherein a regularreflection condition occurs with the second light emitting element 2-2side within a period delineated by two broken lines (period from time t1to time t2).

Operation of the bar code reader of the third embodiment will bedescribed below with reference to FIG. 7.

First, under the control of the controlling driving circuit 9 both ofthe first and second light emitting elements 2-1 and 2-2 are driven sothat intermittent light beams are generated at different timings fromeach other from the first and second light emitting elements 2-1 and 2-2as seen from the waveforms (b) and (c) of FIG. 7 and are individuallyirradiated upon the information recording surface 1aon which the barcode 1 is printed. The thus irradiated light beams are reflected by theinformation recording surface 1aon which the bar code 1 is printed andare introduced into the light receiving element 4. The light receivingelement 4 generates a bar code read signal corresponding to thereflected light beams introduced into it. The bar code read signal issupplied to the amplifier 5, by which it is amplified to a predeterminedlevel. The bar code read signal has such a form wherein reflected lightbeams of intermittent light beams generated from the two first andsecond light emitting elements 2-1 and 2-2 are combined alternately withrespect to time as seen from the curve (d) of FIG. 7 The bar code readsignal amplified by the amplifier 5 is supplied to the first and secondsample hold circuits 12 and 13, by which they are sample held at thegeneration timings of the intermittent light beams from the first andsecond light emitting elements 2-1 and 2-2. Consequently, such first andsecond sample hold signals as seen from the curves (e) and (f) of FIG. 7are obtained from the first and second sample hold circuits 12 and 13,respectively. The first and second sample hold signals are supplied tothe first and second binary digitizing circuits 14 and 15, by which theyare converted into first and second binary signals as seen from thecurves (g) and (h) of FIG. 7, respectively. The first and second binarysignals are supplied to the selecting circuit 16, by which one of themis selected. The thus selected binary signal is supplied to and decodedby the decoding circuit 7 and then outputted as a display signal fromthe bar code reader.

In this instance, the bar code read signals obtained on the output sidesof the first and second sample hold circuits 12 and 13 are supplied alsoto the regular reflection detecting circuit 8, by which it is detectedwhether or not a regular reflection condition occurs with each of thebar code signals. If the regular reflection detecting circuit 8 detectsthat a regular reflection condition does not occur with any of the barcode read signals like the time before the time t1 or after the time t2shown in FIGS. 7(a) to 7(h), it supplies a regular reflectionnon-detection signal to the controlling driving circuit 9 and theselecting circuit 16. On the other hand, if the regular reflectiondetecting circuit 8 detects that a regular reflection condition occurswith any of the bar code read signals like the time between the times t1and t2 shown in FIGS. 7(a) to 7(h), it supplies a regular reflectiondetection signal to the controlling driving circuit 9 and the selectingcircuit 16.

If a regular reflection non-detection signal is supplied to thecontrolling driving circuit 9, then the controlling driving circuit 9continues to drive both of the first and second light emitting elements2-1 and 2-2. On the other hand if a regular reflection detection signalis supplied to the controlling driving circuit 9, then the controllingdriving circuit 9 discriminates, from the timing at which the regularreflection condition occurs, with which one of the first and secondlight emitting elements 2-1 and 2-2 the regular reflection conditionoccurs. Then, the controlling driving circuit 9 immediately stopsdriving of that one of the light emitting elements with which theregular reflection condition occurs, in the example shown in FIG. 7,driving of the second light emitting element 2-2 and keeps the stoppingcondition of driving of the second light emitting element 2-2 for afixed period of time, for example, while reading of the bar codecontinues thereby eliminating the occurrence of the regular reflectioncondition. Meanwhile, if the regular reflection non-detection signal issupplied to the selecting circuit 16, then the selecting circuit 16continues to supply the formerly selected one of the first and secondbinary signals to the decoding circuit 7.

On the other hand, if a regular reflection detection signal is supplied,the selecting circuit 16 stops selection of the binary signal obtainedfrom the intermittent light from that one of the light emitting elementswith which the regular reflection condition occurs, in the example shownin FIG. 7 selection of the second binary signal obtained from theintermittent light from the second light emitting element 2-2. Inparticular, when the first binary signal has been selected until thattime the selecting circuit 16 continues selection of the first binarysignal and supplies the first binary signal to the decoding circuit 7,but when the second binary signal has been selected until that time, theselecting circuit 16 stops selection of the second binary signal andnewly selects the first binary signal so that the first binary signal issupplied to the decoding circuit 7.

It is to be noted that, while, in the third embodiment described above,the first and second light emitting elements 2-1 and 2-2 are employed asthe light emitting elements, the number of light emitting elements whichcan be employed in the present embodiment is not limited to two, andthree or more light emitting elements which generates intermittent lightbeams at different timings from each other may otherwise be employed.

Further, the bar code reader of the third embodiment may be modifiedsuch that, when driving of one of the plurality of light emittingelements is stopped, the driving voltage to the remaining light emittingelement or elements is raised a little.

In this manner, with the bar code reader of the third embodiment, theplurality of first and second light emitting elements 2-1 and 2-2 whichgenerate intermittent light beams at different timings from each other,and when a regular reflection condition occurs with one of the lightemitting elements the regular reflection detecting circuit 8 detects theoccurrence of the regular reflection condition from the bar code readsignal and the controlling driving circuit 9 immediately stops, from thegeneration, timing of the regular reflection condition driving of thelight emitting element with which the regular reflection conditionoccurs while another binary signal which is free from an influence ofthe regular reflection condition is decoded. Consequently, the regularreflection condition thus occurred is detected in a very short time.Accordingly, processing of a bar code read signal can be performednormally in a regular condition free from occurrence of a regularreflection condition and there is no necessity of repetitivelyperforming a reading operation of a bar code as a result of occurrenceof a regular reflection condition.

FIG. 8 shows, in block diagram an optical reading apparatus according toa fourth preferred embodiment of the present invention. Also the opticalreading apparatus of the present embodiment is constructed as a bar codereader. Also in FIG. 8, like elements to those of FIG. 6 are denoted bylike reference characters.

The bar code reader of the fourth embodiment is different inconstruction from the bar code reader of the third embodiment only inthat the decoding circuit 7 is not connected to the output sides of thefirst and second binary digitizing circuits 14 and 15 by way of theselecting circuit 16 but connected directly to the output sides of thefirst and second binary digitizing circuits 14 and 15, and that thedecoding circuit 7 not only has the function of decoding a binary signalbut also has another function of discriminating upon such decoding of abinary signal, whether or not decoding has been performed accurately. Inthis instance, in the fourth embodiment, the amplifier 5, the decodingcircuit 7, the first and second sample hold circuits 12 and 13, and thefirst and second binary digitizing circuits 14 and 15 constitute asignal processing section.

The bar code reader of the fourth embodiment is principally different inoperation from the bar code reader of the third embodiment only in that,while, in the third embodiment, one of first and second binary signalsobtained from the first and second binary digitizing circuits 14 and 15is selected by the selecting circuit 16 and the thus selected binarysignal is decoded by the decoding circuit 7 and outputted as a displaysignal, in the fourth embodiment, first and second binary signalsobtained from the first and second binary digitizing circuits 14 and 15are individually decoded by the decoding circuit 7 and the decodingcircuit 7 selects one of the two binary signals which has been decodedaccurately and outputs the thus selected binary signal as a displaysignal. Since the other operation of the bar code reader of the presentembodiment is almost same as that of the bar code reader of the thirdembodiment described above, description thereof is omitted herein toavoid redundancy.

Operation of the decoding circuit 7 in the bar code reader of the fourthembodiment will be described in more detail here. When the decodingcircuit 7 decodes first and second binary signals successively suppliedthereto in order, it stores the thus decoded binary signals once into aninternal memory not shown thereof and then if it detects that one of thetwo binary signals, for example, the second binary signal has not beendecoded accurately because of occurrence of a regular reflectioncondition, it reads out the decoded first binary signal stored in theinternal memory and outputs the decoded first binary signal as a displaysignal. Or, the decoding circuit 7 decodes first and second binarysignals successively inputted thereto individually at a high speed, andif it detects that one of the two thus decoded binary signals, forexample, the second binary signal, has not been decoded accuratelybecause of occurrence of a regular reflection condition then it extractsthe first binary signal which has been decoded accurately and outputsthe first binary signal as a display signal.

It is to be noted that while in the fourth embodiment described above,the first and second light emitting elements 2-1 and 2-2 are employed asthe light emitting elements and the first and second sample holdcircuits 12 and 13 and the first and second binary digitizing circuits14 and 15 are employed as the sample hold circuits and the binarydigitizing circuits corresponding to the light emitting elements,respectively the number of light emitting elements and the numbers ofsample hold circuits and binary digitizing circuits which can beemployed in the present embodiment are not individually limited to two,and three or more light emitting elements which generate intermittentlight beams at different timings from each other and three or moresample hold circuits and binary digitizing circuits corresponding to thelight emitting elements may otherwise be employed.

In this manner, with the bar code reader of the fourth embodiment, sincea plurality of binary signals obtained in accordance with thearrangement of the plurality of light emitting elements are successivelydecoded by the decoding circuit 7 and one of the binary signals obtainedby such decoding which has been coded accurately is selectivelyoutputted as a display signal, even if a regular reflection conditionoccurs with the plurality of light emitting elements, one of the binarysignals which has been decoded accurately can be selectively outputtedas a display signal without fail. Consequently, there is no necessity ofrepetitively performing a reading operation of a bar code even if aregular reflection condition occurs.

FIG. 9 shows, in block diagram, an optical reading apparatus accordingto a fifth preferred embodiment of the present invention. Also theoptical reading apparatus of the present embodiment is constituted as abar code reader. In FIG. 9, like elements to those of FIG. 6 are denotedby like reference characters.

The bar code reader in the fifth embodiment is different in constructionfrom the bar code reader in the third embodiment only in that theselecting circuit 16 is connected not by way of the first and secondbinary digitizing circuits 14 and 15 to the output sides of the firstand second sample hold circuits 12 and 13, respectively, but directly tothe output sides of the first and second binary digitizing circuits 14and 15, and that, the output of the regular reflection detecting circuit8 is not connected to both of the input of the controlling drivingcircuit 9 and the control terminal of the selecting circuit 16 butconnected only to the control terminal of the selecting circuit 16. Inthis instance, in the fifth embodiment, the amplifier 5, the binarydigitizing circuit 6, the decoding circuit 7, and the first and secondsample hold circuits 12 and 13 constitute a signal processing section.

The bar code reader of the fifth embodiment having the constructiondescribed above operates in the following manner.

Under the control of the controlling driving circuit 9, both of thefirst and second light emitting elements 2-1 and 2-2 are driven so thatintermittent light beams are generated at predetermined differenttimings from each other from the first and second light emittingelements 2-1 and 2-2 and irradiated upon the information recordingsurface 1a on which bar code 1 is printed. The thus irradiated lightbeams are reflected from the information recording surface 1aon whichthe bar code 1 is printed and are inputted to the light receivingelement 4. The light receiving element 4 generates bar code read signalsin response to the reflected light beams thus inputted thereto, and thebar code read signals are supplied to the amplifier 5, by which they areamplified to a required level. The thus amplified bar code read signalsare supplied to the first and second sample hold circuits 12 and 13, bywhich they are sample held in response to the generation timings of theintermittent light beams from the first and second light emittingelements 2-1 and 2-2 so that first and second sample hold signals areobtained from the first and second sample hold circuits 12 and 13,respectively. Then the first and second sample hold signals are suppliedto the selecting circuit 16, by which one of them is selected. The thusselected sample hold signal is supplied to the binary digitizing circuit6, by which it is converted into a binary signal. Then, the binarysignal is supplied to and decoded by the decoding circuit 7 andoutputted as a display signal from the bar code reader.

In this instance, the first and second sample hold signals obtained onthe output sides of the first and second sample hold circuits 12 and 13are supplied also to the regular reflection detecting circuit 8, bywhich it is detected whether or not a regular reflection conditionoccurs. If the regular reflection detecting circuit 8 detects that noregular reflection condition occurs with the first and second samplehold signals, it supplies a regular reflection non-detection signal tothe selecting circuit 16. However, if the regular reflection detectingcircuit 8 detects that a regular reflection condition occurs with any ofthe first and second sample hold signals, it supplies a regularreflection detection signal to the selecting circuit 16. If a regularreflection non-detection signal is supplied to the selecting circuit 16,the selecting circuit 16 continues to supply that one of the first andsecond sample hold signals which has been supplied until that time. Onthe other hand, if a regular reflection detection signal is supplied tothe selecting circuit 16 as a result of occurrence of a regularreflection condition with one of the first and second sample holdsignals, for example, the second sample hold signal, then when the firstsample hold signal has been selected until that time, the selectingcircuit 16 continues to select the first sample hold signal and supplythe first sample hold signal to the binary digitizing circuit 6, but onthe contrary when the second sample hold signal has been selected untilthat time, the selecting circuit 16 stops selection of the second samplehold signal and newly selects and supplies the first sample hold signalto the binary digitizing circuit 6.

It is to be noted that, while, in the fifth embodiment described above,the first and second light emitting elements 2-1 and 2-2 are employed asthe light emitting elements and the first and second sample holdcircuits 12 and 13 are employed corresponding to the light emittingelements, respectively, the number of light emitting elements and thenumber of sample hold circuits which can be employed in the presentembodiment are not individually limited to two, and three or more lightemitting elements which generate intermittent light beams at differenttimings from each other and three or more sample hold circuitscorresponding to the light emitting elements may otherwise be employed.

In this manner, in the bar code reader of the fifth embodiment, sincethe plurality of light emitting elements 2-1 and 2-2 which generateintermittent light beams at different timings from each other areemployed and, when a regular reflection condition occurs with one of thelight emitting elements, the regular reflection detection circuit 8detects the occurrence of the regular reflection condition from thefirst and second sample hold signals, and one of the sample hold signalswhich is not influenced by the regular reflection condition is binarydigitized and then decoded, a required display signal can normally beextracted without being influenced by the regular reflection conditionwhich occurs actually.

Further in the bar code reader of the fifth embodiment, if occurrence ofa regular reflection condition is detected during reading of a bar code,then reading of the bar code must be performed again. However, suchre-reading of the bar code is required to perform only once, and thereis no need of performing reading of the bar code repetitively by aplurality of times.

While the optical reading apparatus in the embodiments described aboveare each constructed as a bar code reader, the optical reading apparatusaccording to the present invention is not limited to a bar code reader,but may be applied to any other similar apparatus only if it reads alinear recording medium like a bar code.

In summary, in the optical reading apparatus of the first to fifthembodiments described above, the regular reflection detecting circuit 8supplies a regular reflection detection signal which is obtained whenoccurrence of a regular reflection condition is detected, to thecontrolling driving circuit 9 and the controlling driving circuit 9controls driving of the plurality of first and second light emittingelements 2-1 and 2-2 in a driving manner, which is different whether ornot a regular reflection detection signal supplied to the controllingdriving circuit 9 to eliminate the occurrence of the regular reflectioncondition. More particularly, when a regular reflection detection signalis not supplied, the controlling driving circuit 9 drives only one ofthe plurality of light emitting elements 2-1 to 2-2 but when a regularcondition detection signal is supplied the controlling driving circuit 9drives another one of the light irradiation sections different from theone light irradiation section, to eliminate the occurrence of theregular reflection condition, or when a regular reflection detectionsignal is not supplied, the controlling driving circuit 9 drives all ofthe plurality of light emitting elements 2-1 to 2-2, but when a regularreflection detection signal is supplied, the controlling driving circuit9 stops driving of the plurality of light emitting elements 2-1 to 2-2one by one in order until occurrence of the regular reflection conditionis detected no more, to eliminate the occurrence of the regularreflection condition, or else, when a regular reflection detectionsignal is not supplied, the controlling driving circuit 9 drives theplurality of light emitting elements 2-1 to 2-2 intermittently atdifferent timings from each other, but when a regular reflectiondetection signal is supplied, the controlling driving circuit 9immediately stops driving of that one of the light emitting elementswith which the regular reflection condition occurs to eliminate theoccurrence of the regular reflection condition.

Thus, with the optical reading apparatus of the embodiments describedabove, since the controlling driving circuit 9 drives the plurality oflight emitting elements 2-1 and 2-2 suitably such that, when occurrenceof a regular reflection condition is detected by the regular reflectiondetecting circuit 8, the occurrence of the regular reflection conditionmay be eliminated, there is an advantage in that reading of a linearrecording medium to generate a display signal is not disabled at allirrespective of whether or not a regular reflection condition occurs andaccurate reading of the linear recording medium can be performedimmediately.

Further, in the optical reading apparatus of some of the embodimentsdescribed above the plurality of light emitting elements 2-1 and 2-2irradiate intermittent beams of light at different timings from eachother and the signal processing sections 5 to 7 and 11 to 16 have aplurality of conversion processing routes for individually performingconversion processing of a plurality of recording medium read signalsobtained individually for the plurality of light emitting elements andselectively extract and output, as a display signal one of recordingmedium read signals obtained by conversion processing by the pluralityof conversion processing routes which is in a good condition. Moreparticularly, when the plurality of recording medium read signals aredecoded, one of the recording medium read signals which has been decodedregularly is selectively extracted and outputted as a display signal, oroccurrence of one of the plurality of recording medium read signals withwhich a regular reflection condition occurs is detected, and another oneof the plurality of recording medium read signals with which occurrenceof a regular reflection condition is not detected is selectivelyextracted and outputted as a display signal.

Thus, with the optical reading apparatus, there is an advantage in that,since that one of the plurality of recording medium read signals whichis in a good condition is selectively extracted and outputted, readingof a linear recording medium to generate a display signal is notdisabled at all irrespective of whether or not a regular reflectioncondition occurs and accurate reading of the linear recording medium canbe performed immediately.

Having now fully described the invention, it will be apparent to one ofordinary skill in the art that many changes and modifications can bemade thereto without departing from the spirit and scope of theinvention as set forth herein.

What is claimed is:
 1. An optical reading apparatus for reading a linearrecording printed on an information recording surface, the opticalreading apparatus comprising:a plurality of light emitting elements foremitting light beams in different directions toward the informationrecording surface; a light receiving element for receiving reflectedlight from the information recording surface and for generating arecording read signal; a signal processing section for converting therecording read signal from said light receiving element into a displaysignal; and a controlling driving section for driving said plurality oflight emitting elements; wherein said plurality of light emittingelements are driven by said controlling driving section so as to emitintermittent light beams at timings different from each other; andwherein said signal processing section includes a plurality ofconversion processing routes, each of the conversion processing routesincluding means for individually performing conversion processing of aplurality of recording read signals obtained from one said plurality oflight emitting elements, said signal processing section selectivelyextracting and outputting, as a display signal, a selected one of therecording read signals obtained by the conversion processing by aselected one of said plurality of conversion processing routes whichomits a regular reflection condition.
 2. An optical reading apparatusaccording to claim 1, wherein the selected recording read signalextracted as a display signal by said signal processing section is oneof the recording read signals which has been decoded regularly upondecoding of the plurality of recording read signals.
 3. An opticalreading apparatus according to claim 1, wherein said signal processingsection detects occurrence of a regular reflection condition from theplurality of recording signals, and the selected recording read signalis one of those of the recording read signals from which occurrence of aregular reflection condition is not detected.
 4. An optical readingapparatus according to claim 1, wherein the linear recording is a barcode, and said optical reading apparatus is a bar code reader.